No matter who you are, if you do something wrong you should have to suffer the consequences or make amends for whatever it is you have done wrong. Especially when it comes to people in high standing or those who posses a lot of power, they should be held accountable for their actions or at least explain to the people the reasons why you did what you did.
No, Sara Netanyahu should not be indicted. It is my opinion that she did not knowingly intend to defraud the Israeli government. Looking at the United States as an example, the expenses that are being questioned are expenses that American taxpayers have covered for our President for years. Unless it is expressly written in Israeli law that the expenses being question must be paid for using private funds, then she should not be indicted. In the long-run, even if they were paid for using private funds, it would still be coming from her husband's government paycheck, so I don't see a difference.
This isn't the first time Sara Netanyahu has been scrutinized for fraud or misuse of funds. If there is clear evidence that she misused public funds, she should face the consequences. As an "official" spouse, her behavior should be above reproach with public funds and she should not be able to essentially steal without facing some punishment.
To be honest, this kind of irregularities we are talking about sound to me more like legitimate mistakes rather than any attempts at fraud. The Netanyahu family has more than enough money to pay for all these things Sara Netanyahu is alleged of doing fraudulently and I just cannot see the woman being fraudulent over little things when the family has plenty to pay for it themselves. If we were talking about huge sums maybe it might be fraudulent but the kind of things we are talking about and the money involved it is nothing and nobody in their right mind would intentionally try to defraud the state for little things like that. I think it legitimately can sometimes be hard to know what is a personal expense and what is a state's expense and sometimes she got it wrong. Legally it might be fraudulent but as far as motive goes it is probably innocent.